The main responsibility of the Contractor is to support the needs of DTP for substructure, full structure and data item searches. Bibliographic searches are also performed utilizing various data bases such as NLM/MEDLARS, CAS ONLINE, DIALOG, etc. The Contractor will also generate systematic nomenclature for selected compounds. The substructure search task is the most significant project activity. Substructure searching supports the full range of DS&CB drug development activities: acquisition of novel compounds; selection of existing (file) compounds for screening; structure-activity correlation studies; grants/contract analysis; searching for analogs of candidate compounds; identifying candidates for radiosensitizer and radioprotector screening; searching for derivatives/analogs of compounds for resyntheses; developing statistics for acquisition and biological activity data; generating data for investigator's requests; developing data for special reports. Full structure searching primarily supports the DS&CB acquisition of chemicals. The data item searches are used to retrieve a wide variety of nonstructural data items such as inventory, confidentiality code, CAS Registry Numbers, declassification history, shipping history, acquisition code, etc. Substructure, full structure and bibliographic searches also support the Biological Evaluation Committees for Cancer and AIDS, the National Cooperative Drug Discovery groups, the National Products Committee and other DTP working groups. Searches for the Natural Products Committee may address BIOSIS, AGRICOLA, MEDLINE, or AIDSLINE. These searches, by genus or specie, are for information on the anticancer effects, HIV effects, other viral effects, microbial effects and biochemical effects for fractions, mixtures or pure chemicals derived from plant or marine products. About 85% of the queries processed use the DTP database, Drug Information System (DIS). The remaining queries address other data bases such as CAS ONLINE, DIALOG, NLM/MEDLARS.